通过检测甜瓜中与拟南芥韧皮部特异性表达蛋白的编码基因AtPP2相类似的基因(AtPP2-like)的表达情况,以及甜瓜植株的胼胝质沉积效应,证明了这二者与甜瓜植株对蚜虫抗性之间的联系.利用反转录PCR (RT-PCR)的方法,检测了甜瓜两个AtPP2类似蛋白的编码基因lec17和lec26,受到HrpNEa的诱导表达增强,同时通过苯胺蓝染色鉴定了胼胝质在HrpNEa处理的甜瓜植株中沉积增加.接种蚜虫后的表型观测结果表明HrpNEa处理的甜瓜生长加快,抗虫效应增加.口针刺吸活动的电波信号图(Electrical penetration graph,EPG)结果显示,HrpNEa处理的甜瓜与对照相比蚜虫的取食活动明显减少,刺探性活动增加,取食频率大幅降低.这些结果表明HrpNEa处理增强了甜瓜对蚜虫的抗性.
:It has been reported that HrpNEa could induce the insect resistance of Arabidopsis. Here we demonstrated that HrpNEa also showed potential to enhance the aphid repellency on Cucumis melo. The expression of AtPP22like gene ( lec17 and lec26) in Cucumis melo determined by RT2PCR and the callose deposition in phloem measured by aniline blue staining were both induced by HrpNEa. The action of aphids after placed on Cucumis melo indicated that HrpNEa could in2 duce insect resistance on Cucumis melo. EPG (electrical penetration graph) results revealed that HrpNEa could decrease the feeding frequency of aphids. Thus,we draw the conclusion that HrpNEa could enhance the resistance of Cucumis melo to aphids.
[1] Wei Z M,Lacy R J,Zumoff C H,et al.Harpin,elicitor of the hypersensitive response produced by the plant pathogen Erwinia amylovora[J].Science992,257:85-88.
[2] Powell G,Tosh C R,Hardie J.Host plant selection by aphids:behavioral,evolutionary and applied perspectives[J].Annu Rev Entomol,2006,51:309-330.
[3] Tjallingii F.Salivary secretions by aphids interacting with proteins of phloem wound responses[J].J Exp Bot,2006,57:739-745.
[4] Wang B,Boulter D,Gatehouse J A.Characterization and sequencing of cDNA clone encoding the phloem protein PP2 of Cucurbita pepo[J].Plant Mol Biol994,24:159-170.
[5] Rose J K C.The Plant Cell Wall[M].Oxford:CRC Press,2003,ISBN 9781841273280.
[6] Thompson G A,Goggin F L.Transcriptomics and functional genomics of plant defense induction by phloem-feeding insects[J].J Exp Bot,2006,3:1-12.
[7] Dong H P,Peng J,Bao Z,et al.Downstream divergence of ethylene signaling pathway for harpin-stimulated Arabidopsis growth and insect defense[J].Plant Physiol,200436:3628-3638.
[8] Dong H P,Yu H,Bao Z,et al.The ABI2-dependent abscissic acid signaling controls HrpN-induced drought tolerance in Arabidopsis[J].Planta,2005,221:313-327.
[9] Bauer D W,Wei Z M,Beer S V,et al.Erwinia chrysanthemi harpinEch:an elicitor of the hypersensitive response that contributes to soft-rot pathogenesis[J].Mol Plant-Microbe Interact995,8:484-491.
[10] Dong H,Delaney T P,Bauer D W,et al.Harpin induces disease resistance in Arabidopsis through the systemic acquired resistance pathway mediated by salicylic acid and the NIM1 gene[J].Plant J999,20:207-215.
[11] El-Sharkawy I,Manríquez D,Flores F B,et al.Functional characterization of a melon alcohol acyl-transferase gene family involved in the biosynthesis of ester volatiles.Identification of the crucial role of a threonine residue for enzyme activity[J].Plant Molecular Biology,2005,59(2):345-62.
[12] Chen L,Qian J,Qu S P,et al.Identification of specific fragments of HpaGXooc,a harpin protein from Xanthomonas oryzae pv.oryzicola,that induce disease resistance and enhanced growth in rice[J].Phytopathology,2008,98:781-791.
[13] Peng J L,Dong H S,Dong H P,et al.Harpin-elicited hypersensitive cell death and pathogen resistance requires the NDR1 and EDS1 genes[J].Physiol Mol Plant Pathol,2003,62:317-326.
[14] Read S M,Northcote D H.Subunit structure and interactions of the phloem proteins of Cucurbita maxima (pumpkin)[J].Euro J of Biochem98334:561-569.
[15] Dinant S,Clark A M,Zhu Y,et al.Diversity of the superfamily of phloem lectins (phloem protein 2)in angiosperms[J].Plant Physiol,200331(1):114-28.
[16] McNairn R B,Currier H B.Translocation blockage by sieve plate callose[J].Planta968,82:369-380.
[17] Douglas E.Phloem-sap feeding by animals:problems and solutions[J].J Exp Bot,2006,57:747-754.
[18] Will T,van Bel A J E.Physical and chemical interactions between aphids and plants[J].J Exp Bot,2006,57:729-737.
[19] Tjallingii W F,Hogen Esch T H.Fine structure of aphid stylet routes in plant tissues in combination with EPG signals[J].Physiological Entomology9938:317-328.
[20] Yan F S.The probing movement and expression and track research method in the stylet of aphid[J].Chin J Zool995,30:40-44.
[21] Zitter T A,Beer S V.Harpin for insect control[J].Phytopathol998,88:S104-S105.
